The future of Kentucky’s controversial changes to a water quality standard is up in the air, after a settlement last year sent the changes back for federal review.
Selenium is a naturally occurring substance that’s released into waterways during strip mining. In large amounts, it’s toxic to both aquatic life and humans. The substance also bioaccumulates up the food chain, so as fish eat other fish, levels of selenium rise.
In November 2013, the Environmental Protection Agency approved changes to Kentucky’s water quality standard that changed the way selenium was measured. The state had requested permission to do away with the chronic — or long-term — standard, and instead institute a two-part process: If water testing reveals levels above a certain benchmark, it triggers fish tissue testing.
The EPA signed off on the changes, but environmental groups sued. In October, all the parties reached an agreement that sent Kentucky’s selenium standard back to the EPA for reconsideration. Part of that involves consulting the Endangered Species Act, which the agency was required to do and hadn’t completed the first time around.